36
List the numbers
31,34,34,35,37,38,38,39
Mark out one from each side till you get 37 and 35 average them to get your answer
(6x–1)(6x+1) - 4x(9x+2) = −1
Simplify the left side:
36x^2-1 -36x^2-8x = -1
Combine like terms:
-1 -8x = -1
Add 1 to both sides:
-8x = 0
Divide both sides by -8:
x = 0 / -8
x = 0
The root is 0
Area is 3.6*3.6*pi
Area is 12.96 pi